DC UPS for 48V PoE switch?

[Neville Bailey]

I have a PoE switch that I would like to keep powered up with a DC UPS. Most DC UPS’s that I have seen only cater for 12V devices, but this switch is 48V.

Any recommendations?

 

[TheChamp]

I have a PoE switch that I would like to keep powered up with a DC UPS. Most DC UPS’s that I have seen only cater for 12V devices, but this switch is 48V.

Any recommendations?

4 of the small gate motor batteries in series will give you the 48V.

Take care when working with DC, especially 48V, put the necessary protection in your wiring.

 

[agentrfr]

I have a PoE switch that I would like to keep powered up with a DC UPS. Most DC UPS’s that I have seen only cater for 12V devices, but this switch is 48V.

Any recommendations?

Take an output from the UPS and boost it to 48V with one of these: https://www.communica.co.za/products/bmt-dc-dc-600w-boost-12-80v-10a

If you need help just give me a shout

4 of the small gate motor batteries in series will give you the 48V.

Take care when working with DC, especially 48V, put the necessary protection in your wiring.

Nah, then he's got to figure out some sort of charging mechanisim and low voltage protection for it

 

[TheChamp]

Take an output from the UPS and boost it to 48V with one of these: https://www.communica.co.za/products/bmt-dc-dc-600w-boost-12-80v-10a

If you need help just give me a shout



Nah, then he's got to figure out some sort of charging mechanisim and low voltage protection for it

Is that going to increase 12V to 48V?

 

[richjdavies]

Is that going to increase 12V to 48V?

You'll have to get a multi meter and adjust the screws on the potentiometer until it is 48v...

(As it says on the spec - adjustable in 2v bands)

 

[Neville Bailey]

4 of the small gate motor batteries in series will give you the 48V.

Take care when working with DC, especially 48V, put the necessary protection in your wiring.

Thanks, but I was hoping for a plug and play device, similar to those Gizmo DC UPS's, but one that can handle 48V.

 

[Neville Bailey]

Take an output from the UPS and boost it to 48V with one of these: https://www.communica.co.za/products/bmt-dc-dc-600w-boost-12-80v-10a

If you need help just give me a shout

Seems like a bit of an inefficient and complex option - at the moment I am running an extension lead from my deep-cycle 12V battery/inverter combo from another room, which works but it's untidy. Surely there must be a plug and play 48V DC UPS out there?

 

[Pineapple Smurf]

You'll have to get a multi meter and adjust the screws on the potentiometer until it is 48v...

(As it says on the spec - adjustable in 2v bands)

Minimum voltage difference is 2volts
Meaning for example if your input is say 24 volts then your output will be minimum 26 volts, you cant for example choose 25volts as your output as the difference will only be 1 volt

These type of DC DC converters are fine tuned with a small flathead screwdriver on a potentiometer and you can get pretty good outputs from them, nicely tuned of increments of around 0.1volts.

It is also good to meausre the load on the output side again once you have connected your device as there is sometimes a volt or 2 loss when under load, compared to when you were finetuning our output before there was a load

EDIT: I just see this now

• Output Voltage: DC 12 ~ 80 V ( adjustable, O/p Voltage > I/p Voltage by 2V )

My bad, I guess it is 2volts increments then on this particular model

 

[TheChamp]

You'll have to get a multi meter and adjust the screws on the potentiometer until it is 48v...

(As it says on the spec - adjustable in 2v bands)

Is there a catch somewhere?

 

[Giggsie]

I have a PoE switch that I would like to keep powered up with a DC UPS. Most DC UPS’s that I have seen only cater for 12V devices, but this switch is 48V.

Any recommendations?

I know this is an old post but I am posting this to help anyone else who is searching the forum for a similar answer. I have found these 48V DC UPSes from a company called Tech-Buddies and really impressed with the unit I have bought.

There is a lot of info on the site with real world case studies which I found (through my own experience now) to be accurate.

Tech-Buddies

Tech-Buddies was formed in 2022 by 2 DIY enthusiasts who were looking for 48V DC to DC UPS solutions to meet some unique requirements due to the ongoing soad shedding crisis in South Africa.

tech-buddies.co.za

Power-Buddie Mini DC UPS 75Wh - DIY Set

The Power-Buddie is a 75 WH Mini DC UPS equipped with LiFePO4 batteries which provide longer run time and deeper depth of discharge over the traditional Gel and Lead Acid batteries found in other UPSes. The 12V - Set comes with a 12V splitter cable and a 9V/12 straight cable. 100W Maximum...

tech-buddies.co.za

8 Port 48V POE Switch, Internet, Home Automation Platform and Access Point

Case study and example off how Power-Buddie DC UPS can provide power backup for an automation platform

tech-buddies.co.za

Hope this helps